Growth, yield and quality of three greenhouse cucumber cultivars in relation to type of water applied at different stages of plant growth

Abstract

Two levels of salinity in the irrigation water (I: well water with EC 2.61 mmhos/cm, II: desalinized water with EC 0.39 mmhos/cm) were applied to greenhouse cucumber cultivars; Alasil, Alia and Copra; at various stages of growth and for different time duration to study the effect of water salinity on growth, yield and quality in cucumber. Five irrigation treatments (IT) were applied; (IT1) irrigation with desalinized water for the whole experimental period; which was 105 days, (IT2) irrigation with desalinized water until the beginning of flowering stage (30 days) then irrigation with local well water, (IT3) irrigation with desalinized water until the beginning of fruit setting stage (35 days) then irrigation with local well water, (IT4) irrigation with local well water 35 days then irrigation with desalinized water until end of experiment, (IT5) irrigation with well water for the whole experimental period. Vegetative growth traits recorded were: plant height, leaf number, leaf area, leaf fresh and dry weight. Fruit growth traits were; length, diameter, firmness, number, fresh and dry weight. Early and total yield were also recorded. Salinity during the entire growing period (IT5) significantly reduced early and total yield by 46.8 and 28.3 % respectively. Also, it reflected higher negative results in all studied traits, except fruit dry weight. The negative effect of salinity on most traits was less severe when IT4 was applied. No significant differences were found between IT2 and IT3, and they resulted in intermediate negative effect in all studied traits; except for early yield. Significant differences among cultivars were found in fruit growth traits especially yield and its components. Highest value for fruit weight, early and total yield were recorded in Copera followed by Alia and Alasil, respectively. Considering that all traits were less severely affected by IT4 and that total yield was only reduced by 7.2% , as compared to IT1, it can be concluded that the use of salinized irrigation water until fruit setting stage followed by desalinized water for greenhouse cucumber production is recommended to save the high cost of water desalinization.